ERNST & YOUNG LLP 787 Seventh Avenue Phone: 212 773-3000 New York, New York 10019 September 16, 1998 Securities and Exchange Commission 450 Fifth Street, N.W. Washington, DC 20549 Gentlemen: We have read Item 4 of Form 8-K dated September 11, 1998, of MarketSpan Corporation and are in agreement with the statements contained in the second sentence of the first paragraph, and the second paragraph as they relate to Ernst & Young LLP and Long Island Lighting Company. We have no basis to agree or disagree with other statements of the registrant contained therein. /s/ ERNST & YOUNG LLP Ernst & Young LLP is a member of Ernst & Young International, Ltd. Page 5